When a stink bug is threatened or killed, it emits an odor that is similar in scent to a skunk. There are varied opinions on the stink bug's specific odor, and some compare the scent to cilantro or outdoor plants.
Stink bugs possess a gland in their abdomens that releases a pungent chemical during times of distress. Certain species of stink bugs are capable of emitting spray that travels many inches.
Stink bugs can grow as long as 2 centimeters and often enter homes during the winter months. When stink bugs prepare to return to the outdoors during periods of warm weather, they often congregate on windows and walls.